Retrieve a list of files

I should like to create an HTML webpage where I can wrap a specific list of files into a folders (to show for example in a tablular view)

The workflow it seems very easy because:

1. I can go in Dropbox API Explorer - list_folder
2. after I get a token (OK after I have to manage the cursor. .. but I suppose this is not the point here)
3. eventually I can check if my JSON is ok (copy and paste for example into converttojson)
4. The problem is when I try to build an easy fetch function to wrap it into an html web page. I can't find a workable example and always I end with an error.

So please can you help me with this last step with a functional FETCH example?

Thanks.

Mauro